Cosmic Ray Electrons, Positrons and the Synchrotron emission of the Galaxy: consistent analysis and implications
Abstract
The study of the physics of Galactic cosmic rays is one of the most active research areas at present. Sensible advances in the field have come in connection to the wealthy of high-accuracy data recently collected by several new instruments, with further progresses expected in the upcoming future. In our recent work (arXiv:1210.4546, accepted for publication in JCAP) a multichannel analysis of cosmic ray electron and positron spectra and of the diffuse synchrotron emission of the Galaxy has been performed by using the publicly available DRAGON code. In light of the recently published data from the Fermi-LAT and PAMELA collaborations, we show that above 4 GeV the electron source spectrum is compatible with a power-law of index ∼ 2.5, the so-called standard scenario, in which cosmic ray electron are produced by galactic supernova remnants. Below the same energy the electron primary spectrum instead must be significantly suppressed so that the total spectrum will turn out to be dominated by secondary particles. The positron spectrum measured below few GeV is therefore consistently reproduced only within low re-acceleration models. Furthermore, one of the primary goals of our analysis is to constrain, by reproducing the radio data, the scale-height z_t of the cosmic ray distribution; we show that a thin galactic halo (z_t < 2 kpc) is excluded. If published at ICRC time, forthcoming AMS-02 results will be also discussed in this context.
- Publication:
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AAS/High Energy Astrophysics Division #13
- Pub Date:
- April 2013
- Bibcode:
- 2013HEAD...1311203D